Products > Test Equipment
IFR 7550 - dead keyboard
KD9CJX:
Hi! I'm working on some projects I haven't had a chance to work on. I have an IFR 7550 spectrum analyzer with a dead keyboard. Boots up fine but will not respond to any input from the front. Previous owner suspected it might be a dead 3v lithium and I tracked it down to the digital motherboard that the keyboard is connected to by a ribbon cable (remember those!)
Fortunately I have a working 7550 and I'd just like to swap the boards to see if that is in fact the issue before I break out the soldering iron. I did check the battery and she's stone cold dead, but again...before I start undoing something that "professionals" soldered during the cold war, I'd like to make sure.
If they were the same firmware/revision, I'd just go right ahead, but the unit in question has PCB REV C and firmware version 3.7. Donor board is REV A and running firmware 2.80. Don't want to go creating two parts units if you know what I mean. Magic smoke is hard to come by right now with Coronavirus provisions.
73
Joe
KD9CJX
korlatos:
Hi Joe, you will need to replace the dead battery. I would recommend installing a 23mm coin cell holder. Once you install the holder and a fresh battery, follow the instructions from the last page of the service manual (attached) to reset the unit.
KD9CJX:
A little update - I was feeling saucy after a day of wondering if I'll be unemployed to all this virus stuff, so I figured what the heck. Put the other digital motherboard in and it fired right up and the keyboard works!
I'll replace the battery next time I'm out and will go from there. After that, I have an IFR 1200S that needs the power supply looked at.
Will post another update once it's done.
73
jimmc:
Thanks for the information, my A7550 has the same unresponsive keyboard so I shall take a look.
In a similar vein does anyone have images of the EPROMs, I've not seen them for the A7550 (and the EPROMs are getting pretty old).
At the risk of hijacking the thread does anyone have a service manual for my other analyser the IFR A8000.
Jim
korlatos:
My plan is to create EPROM images fairly soon - maybe this weekend. I believe there are three of them - two on the CPU board and one on the Video board. My A-7750 unit has the 3.70 firmware. Unfortunately, I don't have the A-8000 service manual.
Navigation
[0] Message Index
[#] Next page
Go to full version